A general calculation model on the effect of main steam pressure variation on the coal consumption rate of steam turbines

2017 ◽  
Vol 35 (1) ◽  
pp. 219-224
Author(s):  
Chao Sun ◽  
Qianying Li ◽  
Wei Lu ◽  
Xintong Liu ◽  
Bin Liu ◽  
...  
2021 ◽  
Vol 261 ◽  
pp. 04012
Author(s):  
He An Wu ◽  
Feng Wei Zhong ◽  
Y. Li

In order to further reduce the power supply coal consumption rate for 300MW subcritical units, this paper will conduct a comprehensive analysis to improve the main steam and reheat steam parameters of those units based on the basic principles of thermodynamics, steam turbines and water pumps. The analysis shows that for the subcritical unit retrofit method that only raises the main steam and reheat steam temperature as the basic technical route has better feasibility. On this basis, combined with the actual system and working conditions of the 320MW subcritical unit, a simulation model of the entire plant’s thermal system is established for calculation and analysis. The calculation results show that the heat consumption rate of the high-temperature subcritical retrofit can reach 7526.7kJ/kWh. Combined with China Resources Xuzhou #3 unit high temperature subcritical comprehensive retrofit project (using high temperature subcritical transformation and equipped with special energy saving transformation), A comprehensive analysis of the performance of the unit after retrofit. The analysis shows that the coal consumption rate after the retrofit is reduced by 36g/kWh.


JTAM ROTARY ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 95
Author(s):  
Kemas Ronand Mahaputra

This study purpose to determine the performance of steam turbines Unit 3 of PT.PLN (Persero) Pembangkitan Asam-asam by comparing the results of the data obtained by each performance test. This research was carried out by taking data performance tests in 2012, 2017, 2018 and 2019 and then processing the data and obtaining turbine heat rate values and average turbine efficiency then comparing the values obtained in each year. The data taken is obtained from the rendal operation of PT.PLN (Persero) Pembangkitan Asam-asam, data variables taken are load, main steam temperature inlet, main steam pressure inlet, HP heater feed outlet temperature, HP heater outlet pressure, main steam flow. Temperature and pressure obtained are then searched for enthalpy values. The data obtained to calculate the value of the turbine heat rate and turbine efficiency on average per time from each performance test then averages the value of the turbine heat rate and turbine efficiency each time the data collection performance test is then compared with the data each year.The calculation of the turbine heat rate uses the heat & mass balance method by measuring the value of the incoming and outgoing fluid differences and comparing the load obtained, the efficiency of the turbine is obtained by dividing the energy of 1 kW with a turbine heat rate then multiplying by 100%. The average turbine heat rate calculation result for each performance test which is on May 23, 2012 is 2,701, October 27, 2017 is 3,136, September 5, 2018 is 3,005, May 21, 2019 is 3,113. The average turbine efficiency value on May 23, 2012 is 37.02%, October 27 2017 is 31.39%, September 5 2018 is 33.28%, May 21, 2019 is 32.12%. The performance of PT PLN (Persero) Pembangkit Asam-asam Implementing Unit Unit 3 has decreased from 2012 to 2019 which is 4.9%


2014 ◽  
Vol 521 ◽  
pp. 508-515 ◽  
Author(s):  
Chun Guang Tian ◽  
Xiang Yu Lv ◽  
De Xin Li ◽  
Tian Dong ◽  
Xiao Juan Han

Based on the principle of featured through-current area being constant, calculation model for parameters of regenerative steam extraction of CHP unit in different heating conditions is developed in this paper through using FROTRAN software. The generated output and thermal economy of the CHP unit are calculated by using the method of equivalent enthalpy drop, and the accuracy of the model is verified. With the purpose to analyze the rationality of different calculation methods, the distribution ratio of coal consumption for heat supply and coal consumption rate for power generation are calculated through method of equivalent enthalpy drop, heat quantity method and method of actual enthalpy drop under the same operating condition. Moreover, according to the operation test on the unit, the highest and lowest generated output of the CHP under various loads of heat supply are determined, which will provide a basis to the subsequent thermoelectric units in participating in peak shaving of power grid.


Author(s):  
P. E. Chew

Pulverized fuel firing is the dominant application of supercritical steam cycles. This has been driven by the aims of efficiency improvement and reduction in environmental emissions. The sensitivity of supercritical steam plant to operating conditions is reviewed and the improvements in operating plant efficiency achieved through increase in steam pressure and temperatures and other factors such as auxiliary power demand is illustrated. Steam temperatures have increased by about 40°C during the 1990s and this, together with an increase in main steam pressure and cycle improvement, have led to a net efficiency of 45 per cent (reduced to UK conditions) for the state-of-the-art plant at present. Plants with still more advanced conditions are under construction or are planned, with the prospect of plant efficiency of 50 per cent in the future. This will rely on continued improvement in materials and is supported by a number of European programmes. Some main difficulties in the design of boilers with advanced temperatures, in particular steam temperature at the furnace outlet, furnace tube arrangement, and materials for superheater and reheater outlet sections, are discussed and the state of advanced steam turbines is reviewed. The operational availability of the supercritical plant, at least in Europe, has improved such that it is little different to the subcritical plant. Similarly, significant improvements have been made in controlling emissions by refinement of flue gas clean-up systems and combustion technology.


2019 ◽  
Vol 12 (3) ◽  
pp. 206-212
Author(s):  
V. N. Goloshumova ◽  
Yu. M. Brodov

The stop valve is one of the «critical» elements of the steam turbine installation, the heating conditions of which determine the reliability of the power unit as a whole. The stop valve for cogeneration steam turbines of subcritical parameters of "UTZ" is unified for familiesT-110/120-130, T-185/210-130/15, ПT-140/165-30/15, P-100-130/15. The sequence of analysis of the valve design is presented for conditions, where only the static temperature and steam pressure at the inlet to the valve, the steam flow rate at the outlet of it, the restrictions for movement during heating are known. The results of the analysis of calculations of unsteady gas-thermodynamic and stress-strain state of the valve during the heating of the main steam line of the turbine T-110/120-130 from the cold state according to the standard instructions are shown. The calculations were carried out by the finite element method using a three-dimensional geometric model of the valve body with a slit filter. The height of the holes in the slit filter is 3.5 mm. The equations of the Nusselt criterion for the flange, the steam box, the lower half of the steam box and the fairing when using computers with limited computing resources are presented. It is shown that the peak of the maximum stresses occurs at the initial stage of the stop valve warming up on the inner (heated) surface of the stop valve body in the area of the flange and the cover. The maximum equivalent stresses are 300 MPa. The comparison of calculated temperatures and temperatures measured during the start-up at the CHP is presented; the temperature difference does not exceed 5–6%. It is proposed to analyze the stop valve reliability with a sequence given in this article in the design of new stop valves with significant differences from the existing prototypes.


Author(s):  
Duan Liqiang ◽  
Sun Jing

Abstract This paper makes the energy consumption difference analysis of the key parameters variations of a 1000MW Ultra-Supercritical Double Reheat coal-fired power generation system. By applying the constant power variable condition calculation method for the steam turbine thermal system, the energy consumption difference analysis mode is established. The energy consumption difference of the key parameters variations (such as the main steam pressure, the main steam temperature and the exhaust steam pressure) of a 1000MW ultra-supercritical double reheat coal-fired power generation system at THA load, 75%THA load, 50%THA load and 40%THA load are investigated. The effects of the key parameter changes on the gross turbine heat rate and coal consumption rate at different working conditions are analyzed, as well as the corresponding energy consumption variation characteristic curves, and the variation rules of power generation efficiency are explored. In addition, the energy consumption difference variation rules of system at different working conditions are studied when any two key parameters such as the main steam temperature, main steam pressure, and the exhaust pressure change simultaneously. The research results show that within a certain range of variation, when the main steam temperature or the main steam pressure increase, or the exhaust gas pressure decreases, the energy consumption of the overall system drops. And with the reduction of load, the main steam temperature has the greatest influence on the coal consumption. By studying the effects of the simultaneous change of two key parameters on the energy consumption of the overall system, it is found that under the same load, the change of the exhaust gas pressure has the greatest influence on the system energy consumption. This paper will provide the theoretical guidance for the energy-saving diagnosis and operation optimization of ultra-supercritical double reheat coal-fired power generation system.


Author(s):  
Junjie Yin ◽  
Ming Liu ◽  
Junjie Yan ◽  
Yongliang Zhao

Abstract With the spreading of intermittent renewable power, coal-fired power units should cycle frequently to balance the load between power supply side and demand side. Coal consumption of coal-fired units operating in dynamic processes is influenced by many factors, including thermal system, control system, heat storage variation, etc. Therefore, it is very difficult to evaluate the energy efficiency of coal-fired units operating in dynamic processes. It is important to ascertain the basic coal consumption rate in dynamic processes, which is the basis to evaluate the operation performance of coal-fired units. In this study, an off-design calculation model of 660MW ultra-supercritical coal-fired unit is developed and validated with design parameters. The developed model can be used to predict the coal consumption rates under steady-state off-design conditions. The basic coal consumption means the coal consumption of coal-fired units with operating parameters the same as target values. To calculate the basic coal consumption rate, a load cycling process is differentiated into lots of short time periods and every period is regarded as a steady-state condition with constant load, therefore the coal consumption rates in every period are equal to that of the corresponding steady-state condition. The calculation formula of basic coal consumption rates in is derived for load cycling processes. On the basis of the off-design calculation model and assumption of idealized condition, average coal consumption rates during different processes with constant load cycling rates can be calculated and analyzed. Results show that if the initial and final loads are both settled, the basic coal consumption rate remains unchanged and is independent of load cycling rate. If the load cycling amplitude remains unchanged, the basic coal consumption rate increases as the initial load decrease. The study aims to provide benchmark values for the energy consumption analysis in actual dynamic processes, and further study on coal consumption characteristics in dynamic processes will be developed based on it.


2013 ◽  
Vol 441 ◽  
pp. 277-280
Author(s):  
Xiao Long Tao ◽  
Ya Fu Zhang ◽  
Shan Wang

In allusion to the problem that abandon hydropower computing ignores the grid absorption capacity, the calculation model of the abandon hydropower considering grid absorption capacity is proposed. In generating daily plan for reference, according the quantity that in excess of the plan calculates the abandon hydropower. In the order of each plant coal consumption rate to reduce the thermal power output from high to low. Hydropower to replace this part of thermal power electricity. When the economic benefit and environmental benefit is largest, we calculate the abandon hydropower that can absorbed by the system. Calculate the increasing benefit of the abandon hydropower by the with and without comparison method when a engineering have been operating.


2014 ◽  
Vol 1008-1009 ◽  
pp. 897-900
Author(s):  
Xue Min Gong ◽  
Jiu Lin Yang ◽  
Chen Wang

An optimization was performed for a sintering waste heat power unit with all data obtained in the site and under the unit normal operating conditions. The physical and mathematical model for the process of cooling and generation is established, which makes the net power generation as an objective function of the cooling machine imported ventilation, the thickness of sinter and the main steam pressure. Optimizing for single parameter, we found that each parameter had an optimal value for the system. In order to further optimize the system's operating parameters, genetic algorithm was used to make the combinatorial optimization of the three parameters. Optimization results show that power generation capacity per ton is increased by13.10%, and net power generation is increased by 16.17%. The optimization is instructive to the operation of sintering waste heat power unit.


Author(s):  
Alan R. May Estebaranz ◽  
Richard J. Williams ◽  
Simon I. Hogg ◽  
Philip W. Dyer

A laboratory scale test facility has been developed to investigate deposition in steam turbines under conditions that are representative of those in steam power generation cycles. The facility is an advanced two-reactor vessel test arrangement, which is a more flexible and more accurately controllable refinement to the single reactor vessel test arrangement described previously in ASME Paper No. GT2014-25517 [1]. The commissioning of the new test facility is described in this paper, together with the results from a series of tests over a range of steam conditions, which show the effect of steam conditions (particularly steam pressure) on the amount and type of deposits obtained. Comparisons are made between the test results and feedback/experience of copper fouling in real machines.


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